Evaluation of the clinical value of CCTA as the preferred screening method in patients with chronic coronary syndrome

BACKGROUND: The advantages and disadvantages of direct invasive coronary angiography (ICA) and coronary computed tomographic angiography (CCTA) + ICA were compared in patients with suspected chronic coronary syndrome (CCS) who presented with angina symptoms or who had nonangina chest pain with abnormal electrocardiogram results. METHODS: A total of 1200 patients who met the inclusion criteria at TEDA International Cardiovascular Hospital from January 2021 to December 2022 were randomly divided into two groups at a 1: 1 ratio: the CCTA + ICA strategy (CCTA group) and the direct ICA strategy (ICA group). The baseline data were collected. All patients in the CCTA group underwent CCTA examination first. If these results showed positive obstructive coronary artery disease (CAD), then typical angina with coronary artery stenosis ranging from 50 to 70% or vascular segments could not be analysed due to severe calcification, so ICA was further performed for definitive diagnosis, and the ICA results were taken as the final diagnosis. All patients in the ICA group underwent ICA examination directly. Demographic data, cardiovascular risk factors, biochemical criteria, chest pain classification, coronary vessel lesion severity and drug use were compared between the two groups. All patients were followed for 1 year after discharge to observe major adverse cardiovascular events (MACE). The differences in unnecessary ICA rates, 1-year MACE rates, allergic reactions to contrast agents and hospitalization costs between the two groups were analysed. On the basis of the baseline clinical data of patients included in this study, a risk prediction model for obstructive CAD was established by logistic regression. RESULTS: (1) There were 592 patients in the CCTA group and 594 patients in the ICA group. The percentage of unnecessary ICA procedures was 7. 5% in the CCTA group and 55. 2% in the ICA group (P < 0. 001), which was a decrease of 86. 4%. (2) Eighteen patients in the CCTA group were readmitted for severe angina, 4 of whom underwent unplanned percutaneous coronary intervention (PCI). Eight patients in the ICA group were readmitted for severe angina, 2 of whom underwent unplanned PCI. There were no cardiac deaths, nonfatal myocardial infarctions or strokes in either group over the 1-year follow-up. There was no statistically significant difference in the rate of MACE-free survival between the two groups (97. 0% vs. 98. 7%, log-rankχ²=1. 996, P = 0. 158). (3) Allergic reactions to contrast agent were observed in 28 patients in the CCTA group and 16 in the ICA group (P = 0. 190). (4) The median hospitalization cost in the CCTA group was 1259. 54, and that in the ICA group was 1399. 41, which was a significant difference (P < 0. 001) and a decrease of 9. 99%. (5) Based on the combination of the logistic regression forward selection method and backward elimination method, variables with P < 0. 05, including creatinine, age, physical activity-induced symptoms, hyperlipidaemia, diabetes and smoking history, were selected from the baseline data of patients to predict obstructive CAD. The above variables were used to establish a risk prediction model for obstructive CAD. The area under the ROC curve (AUC) of this model was 0. 721, indicating good predictive ability. CONCLUSION: In patients with suspected CCS, including typical angina, atypical angina and nonangina chest pain with abnormal electrocardiogram results, the use of CCTA as a first-line diagnostic test can reduce the unnecessary incidence of ICA and hospitalization costs without increasing the incidence of MACE. A risk prediction model of obstructive CAD was established on the basis of the baseline data of the patients enrolled in this study, providing a clinical basis for the decision to use CCTA or ICA. Patients with a low probability of obstructive CAD can be given priority for CCTA, whereas patients with a high probability can be given priority for ICA.